Writing
Engineering, delivery, and building things which last.
Exam Room · Advanced GenAI
How to Pay for Serving a Model on Bedrock
Three models are heading for production: a hosted foundation model, a fine-tune halfway through training, and a set of open weights from a research spike. Finance wants one forecast. Each bills on a different unit, and for two of them the unit was settled the moment somebody picked a base model. Serving cost is less a lever you pull afterwards than a constraint you inherit from where the weights came from.
Read article
Consulting and Craft · Hands On
Gig Posters From the Listings Database
A five-nights-a-week music venue owes the world a poster per gig, and the listings database already knows everything the poster needs to say. A Stability image model draws the art, code sets the type from the data, and Luma Ray 2 animates the headline act's poster into a loop for the socials. The one rule that carries it is the one that makes gig posters the perfect fit: poster art is supposed to be art.
Read article
The Greenbox Story · The Right Tool
Threat Modelling: What the LLM Didn't Think About
Payment data, subscriber PII, farm contracts. The more code LLMs generate, the more systematic security thinking matters.
Read article
The Workshop
The Workshop: Walking the Wall
A review session run against a projected, generated event-storm wall. The facilitator scrolls the whole domain top to bottom, runs mechanical audits that turn model defects into questions the room answers, and closes by counting the open-question cards down live. Ninety minutes, and the model is more honest at the end than at the start.
Read article
Under the Hood · The Service Manual
How S3 Actually Works
S3 stores more than 500 trillion objects and answers over 200 million requests a second, on an API that has barely changed in twenty years. Between your PUT and the disk sit erasure codes, a formally checked storage node, and one of the largest distributed systems ever run.
Read article
Flash Cards · Governance
Flash Card: Keeping PII Out of Prompts and Logs
Keep customer PII out of prompts and logs. What is the built-in control?
Read article
The Workshop
The Workshop: Wardley Mapping
A pattern for laying the components of a value chain (the sequence of capabilities a user needs, top visible to the user, bottom foundational) against an evolution axis, so that build-buy-borrow arguments stop being about taste and start being about where each component actually sits.
Read article
Exam Room · Advanced GenAI
Cheat Sheet: Security and Responsible AI
A final-review sheet for securing and governing generative AI on AWS: identity, network, encryption, data boundary, Bedrock Guardrails, injection defence, and the responsible-AI dimensions, condensed to what you need on the morning.
Read article
Exam Room · Advanced GenAI
Lab: Stand Up a Bedrock Knowledge Base
A hands-on lab. The from-scratch lab made you build retrieval by hand; this one hands the same documents to a managed Knowledge Base and asks you to write the two calls that query it. Chunking, an S3 Vectors index, an ingestion job, and the difference between asking for chunks and asking for an answer.
Read article
The Greenbox Story · The Right Tool
Cynefin: Not Everything Needs a Workshop
Clear, complicated, complex, chaotic: the framework that tells you which approach to use and when to stop over-thinking.
Read articleEarlier writing
August 2026
Generating and Understanding Images, Audio, and Video on Bedrock Exam Room · Advanced GenAI Flash Card: Seeing Into a Production Bedrock App Flash Cards · Operations Chunking Code, Tables, and Mixed Content Exam Room · Advanced GenAI Taking a GenAI Feature From Proof of Concept to Production Exam Room · Advanced GenAI Choosing a Guardrail Strategy: Managed, Custom, or Both Exam Room · Advanced GenAI Cheat Sheet: Evaluation, Cost, and Operations Exam Room · Advanced GenAI Lab: The Capstone Exam Room · Advanced GenAI Writing a System Prompt for a Production Assistant Exam Room · Advanced GenAI Lab: Fine-Tune a Model and Read the Loss Curves Exam Room · Advanced GenAI Cutting Cost per Query in a RAG System Exam Room · Advanced GenAI Open Data: The Case for Sharing Under the Hood Choosing a Distance Metric for Embeddings Exam Room · Advanced GenAI Flash Card: Cutting the Bill Without Losing Quality Flash Cards · Operations Choosing Where to Store Conversation State Exam Room · Advanced GenAI Scaling Knowledge: From One Person's Head to Twenty-Five People's Practice Consulting and Craft · In Practice Deciding Whether to Use GenAI at All Exam Room · Advanced GenAI Preventing Data Exfiltration Through an LLM Exam Room · Advanced GenAI Cheat Sheet: Model Customisation Exam Room · Advanced GenAI Lab: Evaluate the Pipeline Exam Room · Advanced GenAI Handling Ambiguous Questions With Clarification Exam Room · Advanced GenAI Ensemble Programming: The Team Navigates, the LLM Types The Greenbox Story · The Right Tool Dense, Sparse, or Hybrid Retrieval Exam Room · Advanced GenAI Lab: Generate the Weekly Box Art Exam Room · Advanced GenAI Choosing a Vector Index: HNSW, IVF, and the Trade-Offs Exam Room · Advanced GenAI Flash Card: Prompts Are Versioned Assets Flash Cards · Implementation Versioning and Rolling Back Prompts and Models Exam Room · Advanced GenAI Governing Model Access Across Many Teams Exam Room · Advanced GenAI Reducing End-to-End Latency in a GenAI App Exam Room · Advanced GenAI Cheat Sheet: Agents and Orchestration Exam Room · Advanced GenAI Lab: Answer a Metric Question With Text-to-SQL Exam Room · Advanced GenAI Designing a Bot-to-Human Escalation Path Exam Room · Advanced GenAI Grounding on Fresh Data: Tools or RAG Exam Room · Advanced GenAI How Reputation Systems Work Under the Hood · Trust How Many Chunks to Retrieve: Tuning Top-K Exam Room · Advanced GenAI Flash Card: Provisioned Throughput vs On-Demand Flash Cards · Implementation Open-Weight or Proprietary: Choosing How You Host a Model Exam Room · Advanced GenAI Building a Feedback Loop From Users to Model Improvement Exam Room · Advanced GenAI Choosing a Model for Code Generation Exam Room · Advanced GenAI Cheat Sheet: RAG and Vector Stores Exam Room · Advanced GenAI Lab: Build a Data-Quality Gate Exam Room · Advanced GenAI Extracting Structured Data From Documents at Scale Exam Room · Advanced GenAI Building Permission-Safe Retrieval on a Bedrock Knowledge Base Exam Room · Advanced GenAI Preparing a Dataset for Fine-Tuning Exam Room · Advanced GenAI Flash Card: Turning Down the Randomness Flash Cards · Implementation Delivering Responses: Sync, Async, or Streaming Exam Room · Advanced GenAI Multi-Region Resilience for a GenAI Service Exam Room · Advanced GenAI Tracing an Agent's Decisions in Production Exam Room · Advanced GenAI Cheat Sheet: Prompt Engineering Exam Room · Advanced GenAI Lab: Wire a Tool the Model Can Call Exam Room · Advanced GenAI Choosing an Embedding Dimension and Its Storage Cost Exam Room · Advanced GenAI Summarising Long Conversations to Fit the Context Window Exam Room · Advanced GenAI Monitoring a Bedrock Pilot in Production Consulting and Craft · Hands On Routing Requests Between a Cheap and a Capable Model Exam Room · Advanced GenAIJuly 2026
Flash Card: Letting an LLM Take Actions Flash Cards · Implementation Cost Guardrails: Budgets, Quotas, and Model Choice Exam Room · Advanced GenAI Content Moderation With Rekognition, Comprehend, and Guardrails Exam Room · Advanced GenAI Red-Teaming a Bedrock Application Exam Room · Advanced GenAI Cheat Sheet: Model Selection and Inference Exam Room · Advanced GenAI Lab: Build RAG From Scratch Exam Room · Advanced GenAI Building a Golden Dataset for LLM Evaluation Exam Room · Advanced GenAI When to Orchestrate With Step Functions Instead of an Agent Exam Room · Advanced GenAI How to Wire Function Calling Through Bedrock Exam Room · Advanced GenAI Keeping a Knowledge Base Fresh Without Re-Embedding Everything Exam Room · Advanced GenAI Flash Card: LLM-as-a-Judge, and the Catch Flash Cards · Evaluation Choosing Between Kiro, Amazon Quick, and Bedrock Exam Room · Advanced GenAI Defining and Measuring High Performance High Performance Teams Cutting Ingestion Cost by Caching and Batching Embeddings Exam Room · Advanced GenAI Handling Throttling and Rate Limits Gracefully Exam Room · Advanced GenAI Building a Voice Assistant: Transcribe, Bedrock, and Polly Exam Room · Advanced GenAI Lab: Give a Bedrock Chatbot a Memory Exam Room · Advanced GenAI Cost Attribution and Tagging for GenAI Workloads Exam Room · Advanced GenAI Defending Against Indirect Prompt Injection in RAG Exam Room · Advanced GenAI Sam, Jas, and the Invisible Work The Greenbox Story · Faster Together Right-Sizing Provisioned Throughput for a Custom Model Exam Room · Advanced GenAI Flash Card: Evaluating Both Halves of RAG Flash Cards · Evaluation A/B Testing Prompts and Models in Production Exam Room · Advanced GenAI Caching LLM Responses Without Stale Answers Exam Room · Advanced GenAI Event-Driven GenAI: Processing Documents Asynchronously Exam Room · Advanced GenAI Encrypting a Bedrock App End to End With KMS Exam Room · Advanced GenAI Building Deterministic Pipelines With Bedrock Flows Exam Room · Advanced GenAI Lab: Get Structured JSON Out With Tool Use Exam Room · Advanced GenAI Monitoring a Production Bedrock App Exam Room · Advanced GenAI LLM-as-a-Judge: Designing a Rubric You Can Trust Exam Room · Advanced GenAI How OAuth Works: Delegating Access Without Sharing Secrets Under the Hood Choosing an Embedding Model for a Multilingual Corpus Exam Room · Advanced GenAI Flash Card: Faithful but Wrong Flash Cards · Evaluation Measuring Hallucination in a RAG System Exam Room · Advanced GenAI Mise en Place Consulting and Craft · Through the Kitchen Surviving a Model Deprecation on Bedrock Exam Room · Advanced GenAI Designing Safe Tool Schemas for an AgentCore Gateway Exam Room · Advanced GenAI Agentic RAG: When Retrieval Needs to Reason Exam Room · Advanced GenAI Lab: Put a Guardrail in Front of a Bedrock Model Exam Room · Advanced GenAI Parent-Document Retrieval: Small Chunks, Big Context Exam Room · Advanced GenAI Metadata Filtering for Multi-Tenant Retrieval Exam Room · Advanced GenAI On-Call and Incident Response: When the Pager Goes Off The Greenbox Story · Faster Together Why Your RAG Returns the Wrong Chunk Exam Room · Advanced GenAI Flash Card: LLM Explainability Is Traceability Flash Cards · Responsible AI Making an LLM Output Reproducible Exam Room · Advanced GenAI SageMaker JumpStart or Bedrock for the Same Model Exam Room · Advanced GenAI Budgeting Tokens for a Long-Document Workload Exam Room · Advanced GenAI Tuning How a Model Samples: Temperature, Top-P, and Top-K Exam Room · Advanced GenAI Searching Images and Text With Multimodal Embeddings Exam Room · Advanced GenAI Where Humans Belong in a GenAI Pipeline Exam Room · Advanced GenAI Lab: Invoke a Foundation Model From Lambda Exam Room · Advanced GenAI Proving Where AI Content Came From Exam Room · Advanced GenAI When a Purpose-Built AI Service Beats a Foundation Model Exam Room · Advanced GenAI How Certificates Work Under the Hood · Trust Flash Card: What Guardrails Enforce Flash Cards · Responsible AI Buy or Build: Amazon Quick Versus a Custom RAG App Exam Room · Advanced GenAI Running Agents in Production With Bedrock AgentCore Exam Room · Advanced GenAI Orchestrating Multiple Bedrock Agents Exam Room · Advanced GenAI Tuning Fine-Tuning: Epochs, Learning Rate, and Batch Size Exam Room · Advanced GenAI Securing a Bedrock App: IAM, PrivateLink, and Keys Exam Room · Advanced GenAI Defending a Bedrock App Against Prompt Injection Exam Room · Advanced GenAI Retrieval Over Structured Data With Text-to-SQL Exam Room · Advanced GenAI Reading Inspection Photos with a Multimodal Model Consulting and Craft · Hands On Picking the Right Tool to Check and Govern GenAI Data Exam Room · Advanced GenAI Flash Card: Measuring Bias With fmeval Flash Cards · Responsible AI Which AWS Store Can Do Vector Search Exam Room · Advanced GenAI Choosing a Chunking Strategy for Bedrock Knowledge Bases Exam Room · Advanced GenAI Getting Documents Into a Bedrock Knowledge Base Exam Room · Advanced GenAI Prompt Caching Versus Response Caching on Bedrock Exam Room · Advanced GenAI Managing Prompts With Bedrock Prompt Management Exam Room · Advanced GenAI Fine-Tuning, Continued Pre-Training, or Distillation Exam Room · Advanced GenAI Choosing an Inference Option for a GenAI Workload Exam Room · Advanced GenAI Choosing a Model From the Bedrock Catalogue Exam Room · Advanced GenAI Extracting Lease Terms with Bedrock Consulting and Craft · Hands On Prompt Engineering Techniques That Move the Needle Exam Room · Advanced GenAI Flash Card: The Eight Responsible-AI Dimensions Flash Cards · Responsible AI Hybrid Search and Reranking for Bedrock RAG Exam Room · Advanced GenAI Evaluating a RAG Pipeline End to End Exam Room · Advanced GenAI Flash Card: Turning Logs Into an Audit Flash Cards · Governance The Workshop: Retrospectives The Workshop API Contracts: Two Squads, One Direction The Greenbox Story · Faster Together Flash Card: Who Changed It vs What It Said Flash Cards · Governance Keeping PII Out of LLM Prompts and Logs Exam Room · Advanced GenAI How Databases Actually Work Under the Hood Flash Card: The Prompt-and-Completion Record Flash Cards · Governance Code Is Read More Than It Is Written Consulting and Craft · In Practice Wardley Mapping: Build, Buy, or Borrow? The Greenbox Story · Faster Together Flash Card: Freshness and Access Are Metadata Flash Cards · Retrieval How to Match Bedrock Pricing to Workload Rhythm Exam Room · Advanced GenAI How Encryption Works Under the Hood · Trust Flash Card: Hierarchical Chunking in One Line Flash Cards · Retrieval Catching Rent Arrears Without a Model Consulting and Craft · Hands On Flash Card: What a Reranker Actually Fixes Flash Cards · Retrieval Checking a Bedrock Feature for Bias and Explainability Exam Room · Advanced GenAI Keeping an AI Pilot Working After It Ships Consulting and Craft · Hands On Flash Card: Why Hybrid Search Finds ERR-4021 Flash Cards · Retrieval Making a Bedrock App Audit-Ready Exam Room · Advanced GenAI Picking an Embedding Model for Retrieval Exam Room · Advanced GenAI Flash Card: S3 Vectors and the Latency Budget Flash Cards · Vector stores The Workshop: Decision Tables The Workshop Value Stream Mapping: Finding Where to Focus The Greenbox Story · Faster Together Flash Card: The Silent Distance-Metric Bug Flash Cards · Vector stores When a Document Won't Fit the Context Window Exam Room · Advanced GenAI How Git Works Under the Hood Flash Card: When Aurora pgvector Wins Flash Cards · Vector stores The Language of Tests Consulting and Craft · In Practice Strategic Alignment: The Spreadsheet Anika Never Showed The Greenbox Story · Faster Together Flash Card: OpenSearch Serverless's Hidden Floor Flash Cards · Vector stores Streaming Responses to Cut First-Token Latency Exam Room · Advanced GenAI How Identity Works Under the Hood · Trust Answering Tenant Questions from the Lease with Bedrock Consulting and Craft · Hands On Triaging Maintenance Requests with a Bedrock Classifier Consulting and Craft · Hands On The Workshop: DDD Modelling The Workshop Service Design: Customer Support at Scale The Greenbox Story · Growing Pains Importing Custom Weights into Bedrock Exam Room · Advanced GenAI How Email Works Under the Hood Resting the Meat Consulting and Craft · Through the Kitchen Developer Onboarding: Ramping Up Without Slowing Down The Greenbox Story · Growing Pains How to Cut a Bedrock Bill Without Hurting Quality Exam Room · Advanced GenAI Why Trust Is Hard Under the Hood · Trust The Workshop: AI Use Case Envisioning The Workshop Hiring Mistakes: The Hire Who Doesn't Work Out The Greenbox Story · Growing Pains How to Build a Multi-Modal Bedrock Assistant for Insurance Claims Exam Room · Advanced GenAI The Workshop: C4 Modelling The Workshop Capacity Planning: The Seasonal Crunch The Greenbox Story · Growing Pains Evaluating LLM Output With Bedrock Eval Jobs Exam Room · Advanced GenAI Past the Ten-Second Wall Under the HoodJune 2026
Technical Debt Is a Loan, Not a Crime Consulting and Craft · In Practice When a Container Earns Its Own Zoom The Greenbox Story · Drawing the Lines How to Manage Prompts Across Thirty Services on Bedrock Exam Room · Advanced GenAI The Transformer Attention Budget Under the Hood Domain-Driven Design: CQRS and Read Models in Go The Greenbox Story · Drawing the Lines Domain-Driven Design: Event Sourcing the Ledger in Go The Greenbox Story · Drawing the Lines The Workshop: Event Storming an Architecture The Workshop Architecture Decision Records: Why We Did It That Way The Greenbox Story · Drawing the Lines Picking a Vector Store for Bedrock RAG Exam Room · Advanced GenAI When Not to Use an LLM Under the Hood · The AI Field Guide The Probe in the Meat Consulting and Craft · Through the Kitchen Decision Tables: The Substitution Engine in Go The Greenbox Story · Drawing the Lines How to Wire an LLM to Side-Effecting Actions with Bedrock AgentCore Exam Room · Advanced GenAI How Containers Work Under the Hood Building RAG When the Source Documents Change Daily Exam Room · Advanced GenAI Decision Tables: Making Maya's Brain Explicit The Greenbox Story · Drawing the Lines The Workshop: Prioritisation The Workshop Spreading Bedrock Load with Cross-Region Inference Profiles Exam Room · Advanced GenAI Bayesian Reasoning Under the Hood · The AI Field Guide The Price of Everything Consulting and Craft · In Practice Drawing the System: From Event Storm to C4 The Greenbox Story · Drawing the Lines Configuring Bedrock Guardrails for PII, Topics, and Grounding Exam Room · Advanced GenAI How Estimation Works (And Why It Doesn't) Under the Hood Knowledge, Logic, and Constraints Under the Hood · The AI Field Guide Domain-Driven Design: The Anti-Corruption Layer in Go The Greenbox Story · Drawing the Lines Domain-Driven Design: Events Across Boundaries in Go The Greenbox Story · Drawing the Lines Domain-Driven Design: Modelling the Subscription Context in Go The Greenbox Story · Drawing the Lines Domain-Driven Design: Drawing the Boundaries The Greenbox Story · Drawing the Lines Designing Short-Term and Long-Term Memory for a Bedrock Chat Assistant Exam Room · Advanced GenAI Search and Planning Under the Hood · The AI Field Guide The Workshop: Business Model Canvas The Workshop Time Is Wrong Everywhere All at Once Under the Hood · Time Combining RAG and Fine-Tuning for a Legal Contract Assistant Exam Room · Advanced GenAI How to Build a Citations-Required RAG Over 50K Internal Documents Exam Room · Advanced GenAIMay 2026
Rules, Grammars, and Regex Under the Hood · The AI Field Guide The Salt in the Dish Consulting and Craft · Through the Kitchen Why Does Thursday Last Forever? Under the Hood · Time Picking a Bedrock Model for High-Volume RAG Exam Room · Advanced GenAI Prioritisation: What Changes First The Greenbox Story · Finding the Fit The Boring Baseline That Wins Under the Hood · The AI Field Guide A Gentle Guide to Typography: From Chisels to Character Sets Under the Hood The Clock Inside You Under the Hood · Time Pricing Experiments: The Right Box at the Right Price The Greenbox Story · Finding the Fit Before the Transformer Under the Hood · The AI Field Guide The Workshop: Assumption Mapping The Workshop Can You Turn Back Time? Under the Hood · Time Business Model Canvas: Does This Actually Work? The Greenbox Story · Finding the Fit After the Transformer Under the Hood · The AI Field Guide The Workshop: Jobs to be Done The Workshop Does Time Even Exist? Under the Hood · Time Assumption Mapping: Testing What You Believe The Greenbox Story · Finding the Fit The Reranker You Didn't Know You Needed Under the Hood · The AI Field Guide The Knife in My Hand Consulting and Craft · Through the KitchenApril 2026
Time Is Weirder Than You Think Under the Hood · Time Jobs to Be Done: Why Subscribers Actually Stay The Greenbox Story · Finding the Fit The Other Transformers Under the Hood · The AI Field Guide The Workshop: User Story Mapping The Workshop Ticks or Tocks? Under the Hood · Time Accessibility: A Product Decision, Not a Compliance Tick The Greenbox Story · Shipping What Matters What Day Is It? Under the Hood · Time The Workshop: Impact Mapping The Workshop User Story Mapping: Seeing the Whole The Greenbox Story · Shipping What Matters The Workshop: Sprint Planning The Workshop What Time Is It? Under the Hood · Time The Workshop: Example Mapping The Workshop Impact Mapping: Connecting Work to Goals The Greenbox Story · Shipping What Matters The Workshop: Event Storming a Process The Workshop The Workshop: Event Storming a Domain The Workshop Teaching Your LLM the Codebase: CLAUDE.md and AGENTS.md The Greenbox Story · Shipping What Matters Teaching Your LLM the Codebase The Greenbox Story · Shipping What Matters Behaviour-Driven Development: From Stories to Working Software The Greenbox Story · Shipping What Matters The Quiet Jar in the Fridge Consulting and Craft · Through the Kitchen Sprint Planning: Turning Sticky Notes into Delivery The Greenbox Story · From Chaos to Clarity To LLMs... and Beyond! Under the Hood · The AI Field GuideMarch 2026
Example Mapping: Making Stories Concrete The Greenbox Story · From Chaos to Clarity How LLMs Actually Work Under the Hood · The AI Field Guide Event Storming: Building Shared Understanding The Greenbox Story · From Chaos to Clarity Retrospectives: Catching the Wrong Kind of Fast The Greenbox Story · From Chaos to Clarity The Value Is in Ideas, Not Code Consulting and Craft · In Practice Minimum Viable Product: The First Box The Greenbox Story · From Chaos to Clarity Customer Discovery: Before the First Line of Code The Greenbox Story · From Chaos to Clarity